AHhhh okay I think I have it. If I don't then I guess I'm getting banned from here LOL
So, I think the rule is that: B has to be the Least Common Multiple of both A and C
Gosh. Welll Ima throw what I got just as something we all can think about.
1. B has to be a multiple of both A and C. Or A and C have to be factors of B
2. In all cases, I've seen, where a=b=c it's always true.
3. The 2nd part of this rule can't have something to do with division or...